This application claims the priority of German Application No. 102 10 665.7-35, filed Mar. 12, 2002, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a device having an energy-generating unit and a distributor unit for distributing electrical energy to electrical loads and a method for monitoring the distribution of energy.
The international application WO 99/46140 A1 discloses a hybrid drive for an electric vehicle, which drive has a fuel cell, an energy store, an electric locomotion motor and electric secondary loads. A distributor unit is provided which includes two separate circuits provided with switching devices for optionally connecting the electric locomotion motor and the electric secondary loads to the fuel cell or the energy store. The distributor unit also has a switchable connecting line between the fuel cell and the energy store.
In high-voltage networks, distributor units for distributing electrical energy over flexible lines, for example cables, are connected to electrical loads. The lines usually have connector part halves or plug-type connectors at their ends. These connector part halves/plug-type connectors correspond to connector part halves/plug-type connectors provided at or in housings of the distributor unit or the loads and are detachably connected to them. An example of a stationary distributor unit of this type is a switching cabinet. In transportation devices, the lines are frequently arranged in cable housings and are connected to or into the housings of the loads and of the distributor unit with their associated connector part halves during installation. If necessary, the connector part halves can be separated from one another, for example during maintenance or repair work, and connected to one another again.
In order to ensure that, when a connector part composed of two connected connector part halves is opened, for example by removing a load or pulling off one connector part half, there is no voltage at the connector part half of the distributor unit or of the line which is now exposed, a line loop or a diagnostic circuit, which runs through the connector part halves (and is referred to as interlock), is typically provided. When two connector part halves are separated, the diagnostic circuit is disconnected. This disconnection triggers a disconnection of the current supply or voltage supply of the distributor unit, making the connector part halves current free. This ensures that persons and surroundings are not put at risk by high voltages and that arcing does not occur.
If the separation of two connector part halves is considered as a fault of the normal operating state, this specific type of fault which is associated with a disconnection of the diagnostic circuit or the line loop, is detected by just this disconnection of the diagnostic circuit. However, in the arrangement described at the beginning other faults may occur which can lead to persons and surroundings being put at risk.
For example, short-circuits may occur between the connector part and earth or supply voltage. Other faults may occur in the form of no-load operation, in particular at or in the connector part. In the previously described device, these faults are not detected as they are not associated with a separation of two connector part halves and the associated disconnection of the diagnostic circuit.
The present invention is based on the object of taking measures which detect faults and prevent people and surroundings from being put at risk in a device with an energy-generating unit and a distributor unit for distributing electrical energy to electrical loads. The object of the invention is also to provide a method for monitoring a device which is embodied in this way.
The invention is characterized by the use and the monitoring of defined diagnostic signals in the diagnostic circuit and/or on the conductor loop. This measure can easily be integrated into existing devices for distributing electrical energy to loads. The expenditure on components and the amount of insulation space required are low. Faults which change the time profile of diagnostic signals in a relevant fashion are detected and lead to the current supply or voltage supply of the distributor unit, and thus of the loads, being switched off.
If the diagnostic signal is transmitted, for example to an evaluation unit assigned to a load, even though the diagnostic circuit is separated or disconnected, for example as a result of two connected connector part halves being separated, a fault is detected due to the changed curve shape of the time profile of the diagnostic signal. Furthermore, the current supply or voltage supply of the distributor unit is interrupted, and the safety of persons and the environment is thus ensured.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.